The Guano Trade

The guano trade began on three tiny Peruvian islands in the Pacific, and their product reached farmers’ fields around the world.

The Great Heap, 1865From Alexander Gardner, Rays of Sunlight from South America

The three tiny Chincha Islands lie off the southern coast of Peru. For millennia, they served as home for seabirds. The birds fed and bred in the rich waters packed with fish and absent of predators, allowing their droppings to accumulate to a depth of up to 200 feet. The dry weather and cool ocean currents there maintained the guano’s nitrate-rich quality.

In the early 19th century, farmers and chemists worldwide claimed that Chincha Islands guano was the world’s finest fertilizer. Hundreds of British, German, and American ships purchased it from the Peruvian government for their own agriculture, waiting offshore up to eight months to load the precious cargo. These nations’ ships also sought, claimed, and mined other guano islands in the Pacific and Caribbean.

Although they recognized the practices weren’t sustainable, they continued to harvest the guano. By the late 1870s, nearly all of the Chincha Islands guano was gone, and the seabird habitat was ruined by the mining operations.

Chincha Islands Guanay Cormorants, 1907

This picture of the densely packed guanay cormorants at South Chincha Island, Peru, was published by the U.S. National Museum in 1920 by a fisheries scientist. Today, the U.S. National Museum is better known as the Smithsonian Institution.

Image from Coker, “Habits and Economic Relations of the Guano Birds of Peru” (1920)

Extracting the Chincha Islands Guano, 1865

The vertical channels were cut into the surface of “The Great Heap” of seabird guano by miners pickaxing the solidified droppings from the mound.

Image from Gardner, Rays of Sunlight from South America (1865)

Chinese Guano Miners, 1865

The remarkable height of the guano deposit is shown by the figures of the indentured Chinese miners. After South American prisoners and slaves and Hawaiian workers were no longer available, as many as ninety thousand Chinese men were brought in to work the Chincha deposits.

Image from Gardner, Rays of Sunlight from South America (1865)

Land Transport for the Guano, 1865

Once the guano was pickaxed from the ground, it was shoveled into carts on rails and transported to the edge of the steep cliffs for transfer to the boats below.

Image from Gardner, Rays of Sunlight from South America (1865)

Down the Shoot, 1865

Wheelbarrows of guano were dumped into the wooden “shoot” (chute) at the top of the cliff, from which it slid down into lighters (small craft). The cliffs were too steep for the large ships to approach safely, so the lighters transported the loose guano out to the vessels anchored offshore.

Image from Gardner, Rays of Sunlight from South America (1865)

Waiting for Guano at the Chincha Islands, 1865

In the heyday of the guano trade, up to three hundred ships per year visited the Chincha Islands and waited offshore to load. The ships with exposed waterlines have already discharged their ballast and are ready to load.

When the loading started, all inside doors and windows were closed and tightly covered with canvas to prevent the toxic dust from filling a ship’s crew spaces. Loading crews were limited to twenty-minute shifts in the cargo holds, and the rest of the crew climbed to the tops of the masts to breathe fresh air.